Conversion of hydrocarbon oils



Dec. 8, 193 6. J c MQRRELL 2,063,112

CONVERSION OF HYDROCARBON OILS Original Filed July 24, 1931 FURNACE FURNACE INVENTOR JACQUE C. MORRELL ATTORN Patented Dec. 8, 1936 UNITED STATES PATENT, oFFice I 2,063,112 CONVERSION OF HYDROCARBON OILS Jacque C. Morrell, Chicago, 111., assignor, by

, mesne assignments, to Universal Oil Products Company, Chicago, 11]., a corporation of Delaware Application July 24, 1931, Serial No. 552,806

Renewed January 4, 1934 3 Claims.

together with reflux condensate from said sys-' tern, to independently controlled conversion conditions in such cracking system, and recycling a portion of the residual product for retreatment 15 in the same system, as desired.

In a more specific embodiment, the invention comprises subjecting raw oil charging stock to conversion conditions of temperature and pres-" sure in a primary heating zone, introducing the heated products from said primary zone into an enlarged reaction zone, withdrawing liquid and vaporous products of reaction simultaneously from said reaction zone, introducing the products of reaction into a secondary enlarged or vaporizing zone wherein a reduced pressure is preferably maintained and in which vapors and liquid may separate, withdrawing all or a portion of the residual liquid from said vaporizing zone and recycling the same, as desired, to the aforementioned reaction zone, withdrawing vapors from said vaporizing zone and subjecting the same to fractionation, subjecting the relatively light, fractionated vapors to condensation and collecting the resultant products; withdrawing the relatively heavy, insufficiently converted components of said fractionated vapors and subjecting the same, together with a secondary and separate raw oil charging stock to independently" controlled conversion conditions in a secondary heating zone, and thereafter introducing the heated oil from said secondary heating zone into the aforementioned reaction zone and/or vaporizing zone, or partially into both.

As a feature of 'the present invention, a portion or all of the recycled residual oil, instead of passing directly from the vaporizing zone into the reaction zone, may be introduced into the stream of highly heated oil discharging from the secondary heating zone wherein the secondary charging stock and reflux condensate has been treated, in order that a desired cooling of said stream of highly heated oil and further conversion of said residual oil may be effected.

Other and further objects and advantages of l the invention will become apparent as the description thereof proceeds. The attached drawing is a diagrammatic, side-elevational view of one form of apparatus in which an operation embodying the principles of the present invention may be carried out.

Referring to the drawing, raw oil charging stock (hereinafter, for convenience, designated as the primary charging stock), may be supplied through line I, controlled by valve 2, via pump 3, from which it may be fed through a line 4, 1 controlled byvalve 5, into a line 6, controlled by valve 1, leading into a heating element 8; or, if desired, all or a portion of such primary charg ing stock, instead of passing directly to heating element 8, may pass from pump 3 through a line 9, controlled by valve In, into a preheating coil I2, from whence it may pass through a line [3, controlled by valve l4, into said line B and vthence therethrough into heating element 8.

Preheating coil I2 may be disposed within a fractionator l5, wherein vapors produced in the process are subjected to treatment for fractionation and separation, and may thereby be caused to contact with the relatively hot vapors undergoing treatment therein to bring about a desired heat exchange to cool said vapors and preheat said raw charging oil. If desired, however, a portion of the primary charging stock may be fed directly into said fractionator and caused to directly contact with said'vapors, by intro- 30 ducing said raw charging stock from said line 9 into said fractionator through a line l6, controlled by valve ll, in communication with said line 9, causing said raw charging stock to combine within said fractionator with the relatively heavy components of the fractionated vapors which may be condensed therein, and passing therewith to further treatment as will hereinafter more fully appear.

Heatingelement 8 may be disposed in any suit- 40 able form of furnace l8, and-the primary charging stock introduced therein may be subjected to heat treatment under any desired conversion temperature and superatmospheric pressure. Such temperature, for example, may rangelfrom 800. to 5 950 F., and the pressures utilized therein, for example, may range from to 500 pounds per square inch.

Heated oil from the primary heating element 8 may be discharged therefrom through a line I9, 50 controlled by valve 20, into a reaction zone or chamber 2|,the latter being preferably maintained under substantially the same superatmospheric pressure as. said heating element. If desired, of course, the chamber 2i may be main- 55 tained under a lower superatmospheric pressure than that prevailing within the heating element 9. The reaction products, both liquid and vapor, preferably, may be withdrawn from reaction chamber 2| from its lower portion through a line 22, controlled by valve 23, and introduced, via said line, into a vaporizing chamber 24, which is preferably maintained under a substantially reduced pressure, relative to that employed within the chamber 2!. Preferably, separation of vapors from residual liquid is permitted within the chamber 24, and the vapors may be discharged therefrom through a line 25, controlled by valve 25, for introduction, via said line, into the fractionator l5, wherein they may contact with the incoming raw charging stock, be cooled and condensed, the lightercomponents of said vapors,

after suitable fractionation therein, passing from said fractionator through a line 2!, controlled by valve 30 to a suitable condenser 3|, for cooling and condensation. The cooled and condensed vapors are passed from said condenser 3| through a line 32, controlled by valve 33, into a suitable receiver 34, wherein distillate and uncondensable gases separate, the latter being withdrawn from said receiver through a line 35, controlled by valve 33,

to any suitable purpose, while the distillate may be withdrawn from said receiver through a line 31, controlled by valve 38, to storage or elsewhere, as desired. A portion of the distillate fromreceiv'er 34 may, if desired, be recycled, through any desired means (not shown) to the fractionator l5 to further assist in fractionation of the vapors undergoing treatment within that zone.

A secondary and separate charging stock, which may comprise a stock which is heavier or lighter than the primary charging stock utilized in the primary heating zone, may be supplied to the system through a line 39, controlled by valve 43,

and taken by a pump 4|, discharging into a line 42, controlled by valve 43, and introduced through said latter line into a secondary heating element 48. Such secondary charging stock, of course,

may be preheated by any well-known means (not shown), if desired, prior to its introduction into said heating element 49. The relatively heavy,.-

intermediate and insufliciently converted components of the vapors condensedwithin the fractionator l5 may be withdrawn from the lower portion of said fractionator through a line 52, oontrolled by valve '53, and passed via pump 54 into a line 55, controlled by valve'59, which leads into and communicates with said line 42, to commingle said insufliciently converted components from the fractionator l5 with the secondary charging stock being supplied to the secondary heating element 49 through said line 42. i

Secondary heating element 43 may be disposed within any suitable type of furnace 49, and the ofl supplied thereto may be subjected to any desired conversion. conditions of temperature or pressure, such conditions being either of a milder or more severe nature than those utilized in the primary heating element 9, and depending, of course, upon the nature, characteristics and composition of the particular oil being treated. For example, liquid-vapor-phase conversion conditions may be maintained within said secondary heating. element, of 5 the order of approximately 850 to 950 F., with pressures of the order of about to 500pounds per square inch; or, if

desired, vapor-phase conversion conditions may be maintained therein, such temperatures ranging, for example, 'from approximately 950 to 1200' F., with pressures ranging from sub:.tan-

conditions within secondary heating element 48,

the.heated oil may be discharged therefrom through a line 59, controlled by a valve 5|, for

discharge into line 22, leading into the vaporizing chamber 24; or, if desired, all or any part of said heated oil may be diverted from said line 59 and passed into a line 51,- controlled by valve 59, in communication with said line 50, whereby it will be discharged into line I9, leading into the reaction chamber 2|.

Heavy unvaporized-residual oil may be withdrawn from the vaporizing zone 24 through a line 59, and may be passed from said line, either in whole or in part, as desired, into a line 69, controlled by valve-Sl, leading to storage, or to further treatmentwithout the system. Any desired portion of such residual oil, however, may be taken from said line 59 through control valve 62, by a pump 93, which discharges into a line 94, controlled by valve 61, and introduced either into line 51 to commingle with the highly heated products passing therethrough from secondary heat-;

ing element 49, or passed from said line 64 into a communicating line 65, controlled by valve 96, leading directly into the reaction zone 2 I, to commingle with the, products undergoing reaction;

or, if desired, may be introduced partially into lines 51 and 65, as desired. By comniingling the residualoil from the vaporizing chamber 24 with the highly heated oil passing through line 51 from secondary heating element 48, it is thus caused to contact directly with such higlfly heated oil, thereby subjecting said residual products to further heatingand reconversion, and

would otherwise prevail.

also serving as a cooling medium of such stream .As has been stated, the "reaction chamber 2| may be maintained under substantially the samef pressureas that utilized within the heating zones, or, may be maintained at a slightly lower pressure. The fractionating, condensing and collecting portions of the systeni are prefer- .ably maintained under substantially lower pressures, ranging from substantially atmospheric to about 100 polmds per square inch, orthereabouts.

It is .to be understood, of course, that these figures are merely illustrative, and that the invention may be carried out with pressures at greater variance, depending, of course, upon the particue lar operation desired, the characteristics of the oil under treatment and the product sought.

As a specific example of an operation embodyequalized within the reaction chamber, but re duoed in the vaporizing chamber to approximately 35 poimds per square inch. A secondary charging stock, of about a 48 A. P. r. gravity distil- I late, comprising about 30% of the total raw oil fed to the system, may be subjected, together with reflux condensate from the fractionator, to a temperature of approximately 975 F., under a superatmospheric. pressure of the order of about 100 pounds per-square inch in the secondary heating element of the system, and the heated products introduced into the vaporizing zone. About 40% of the residual oil from the vaporizing chamber may be recycled to the reaction chamber.

From such an operation, a yield of approximately 65% of motor fuel, having an anti-knock value approximately equivalent to a blend of 60% benzol and 35% straight-run Pennsylvania gasoline will be obtained. In addition, about 23% of fuel oil will be produced, the only other product being a rich, uncondensable gas and a. very small percentage of coke or carbonaceous material.

Inanother operation, the secondary charging stock may be discharged directly into the reaction chamber, in which operation the heating element is maintained at substantially the same pressure as the reaction chamber, all other conditions being substantially as stated above. The yield of gasoline will be increased to about 70%, and the benzol equivalent to about 65%.

Fuel oils of a residual character, or lighter'oils may be similarly treated with somewhat increased yields of motor fuel for the heavier oils, and somewhat decreased yields for the lighter charging oils, but with higher anti-knock value in all cases.

I claim as my invention:

1. In a process of hydrocarbon oil conversion wherein oil is subjected to cracking temperatures and pressures in a primary heating zone, thereafter introduced into a reaction zone for further conversion, the products of reaction discharged from the reaction zone into a vaporizing zone maintained under a substantially reduced pressure and wherein liquids and vapors separate, the latter thereupon subjected to fractionation and the heavier insufiiciently converted components of said vapors subjected to recracking in a secondary heating zone of the system, the improvement which comprises passing highly heated oil from said secondary heating zone directly into said vaporizing zone and returning residual liquid products from said latter zone directly and without prior cracking to said reaction zone for further conversion.

2. In a process of hydrocarbon oil conversion, wherein oil is subjected to cracking temperatures and pressures in a primary heating zone, the heated oil from said heating zone being thereafter discharged into a reaction zone for further conversion, the products of reaction being introduced into a vaporizing zone maintained under a substantially reduced pressure below that maintained in said primary heating zone and said reaction zone and wherein liquids and vapors separate, the latter being subjected to fractionation, and

. the heavier, insufiiciently converted components of said vapors condensed by said fractionation treatment subjected to further conversion in a secondary heating zone, the improvement which comprises introducing a portion of the converted oil from said secondary heating zone directly into said vaporizing zone and another portion thereof directly into said reaction zone, and recycling residual liquid from said vaporizing zone directly and without prior cracking to said reaction zone for further conversion.

3. In a process of hydrocarbon oil conversion wherein oil is subjected to conversion conditions of temperature and pressure in a. primary heating zone, thereafter introduced into a reaction zone and the products of reaction discharged from the reaction zone into a vaporizing zone maintained under a substantially reduced pressure and wherein vapors and liquids separate, the vapors being subjected to fractionation and separation and the condensed intermediate and insufficiently converted components thereof subjected to reconversion conditions of temperature and pressure in a secondary heating zone together with a secondary charging oil unlike that subjected to treatment within said primary heating zone, the improvement which comprises introducing separate portions of the highly heated oil from said secondary heating zone into said reaction zone and said vaporizing zone, and withdrawing residual liquid from said vaporizing zone and introducing the same directly and without prior cracking into the highly heated oil being introduced into said reaction zone.

JACQUE C. MORRELL. 

